Electromagnetism

• Transverse wave particles are moving perpendicular to the energy movement being carried. e.g. light waves
• Longitudinal waves have particles vibrating and direction of energy travelling in the same direction. e.g. sound waves
• What is this type of wave?

  Longitudinal wave

  A) Compression

  B) Compression

  C) Rarefaction

  D) wavelength

  
• What type of wave is this?

  Transverse Wave

  A) wavelength

  B) Equilibrium

  C) Trough

  D) Amplitude

  E) Crest

  F) Energy Direction -->

  
• Transverse waves particles move up and down
• ROYGBIV (red, orange, yellow, green, blue, indigo, violet)
• Wavelength (lamda) is the distance between two crests or two troughs in a wave. Measured in metres (m)
• Frequency (f) is the number of waves passing a point in a second. Measured in Hertz (Hz)
• Period (T) is the time for one complete wave to pass a point. Measured in seconds (s)
• Wavelength and Frequency are proportional to each other.
• Frequency and Period are inversely proportional to each other
• f = 1/T
• v = (f)(lamda) --> ( Wave speed = Frequency * Wavelength)
• The angle of reflection is always equal to the angle of incidence
• When the light is moving from a more optically dense medium to a less optically dense medium, the critical angle causes the refracted ray to have an angle of 90 from the normal.
• Total internal reflection occurs when a light source is moving from a more optically dense medium to a less optically dense medium
• The angle of incidence must be larger than the critical angle for the medium. This causes all of the light to be reflected by the boundary instead of reflected outwards.
• Snell's law: n1Sin(θ1) = n2Sin(θ2)
• Electromagnetism spectrum is the measure of the wavelength of different radiation by the sun.
• The longer the wavelength , the more diffraction occurs.
• The narrower the opening, the more diffraction occurs.
• Radiowaves with wavelengths of Km diffract over hills and through valleys so you can easily get reception
• Microwaves with wavelengths of cm tend to go straight.
• Long wave radio waves can bend/diffract around the earth's surface.
• Radio waves can diffract around obstacles like buildings, mountains, or the earth's curvature, allowing them to reach areas that are not in the direct line of sight of the transmitter.

  • This property is useful for communication systems, especially in areas with complex topography or urban environments.
• Link of wavelengths, frequency and diffraction
• Smaller the frequency the greater the diffraction of the wave.
• Both water waves and electromagnetic waves diffract through gaps and around objects.
• Diffraction is the bending of waves around or through a boundary or obstacle.
• The longer the wavelength, the more diffraction occurs.
• The narrower the opening, the more diffraction occurs.
• Wave theory states that wave transfer energy from one point to another without transferring matter.
• The energy of EM light is porprotional to its amplitude (brightness)
• If the frequency of the light waves increase then the voltage will also increase
• Photons are little light packets of energy
• Photons are porprotional to the frequency of the wave ( Number photons increases then frequency will also increase)
• The wave partcicle duality theory states that EM waves have both wave and particles properties.
• EM waves and particles can reflect/refract and diffract (waves) but can also cause atoms to become ionized (particles)
• Some particles can also behave like waves indr certain conditions
• Energy is proportional to the brightness (wave-nature of the light source)